📰 Tweak the suggestion ranks for UMA to handle fetchMore

chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java

Index: chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..452238ffd3a4d5c17d800c7f682cafb976718005
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+++ b/chrome/android/junit/src/org/chromium/chrome/browser/ntp/cards/SectionListTest.java
@@ -0,0 +1,190 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.ntp.cards;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import static org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.createDummySuggestions;
+import static org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.registerCategory;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import org.chromium.base.Callback;
+import org.chromium.base.test.util.Feature;
+import org.chromium.chrome.browser.ntp.NewTabPageView.NewTabPageManager;
+import org.chromium.chrome.browser.ntp.cards.ContentSuggestionsTestUtils.CategoryInfoBuilder;
+import org.chromium.chrome.browser.ntp.snippets.CategoryInt;
+import org.chromium.chrome.browser.ntp.snippets.FakeSuggestionsSource;
+import org.chromium.chrome.browser.ntp.snippets.KnownCategories;
+import org.chromium.chrome.browser.ntp.snippets.SectionHeaderViewHolder;
+import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
+import org.chromium.chrome.browser.ntp.snippets.SnippetArticleViewHolder;
+import org.chromium.chrome.browser.offlinepages.OfflinePageBridge;
+import org.chromium.chrome.browser.suggestions.SuggestionsMetricsReporter;
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Unit tests for {@link SuggestionsSection}.
+ */
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class SectionListTest {
+    @Mock
+    private NewTabPageManager mNtpManager;
+    @Mock
+    private OfflinePageBridge mOfflinePageBridge;
+    @Mock
+    private SuggestionsMetricsReporter mMetricsReporter;
+    private FakeSuggestionsSource mSuggestionSource;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mSuggestionSource = new FakeSuggestionsSource();
+
+        when(mNtpManager.getSuggestionsSource()).thenReturn(mSuggestionSource);
+        when(mNtpManager.getSuggestionsMetricsReporter()).thenReturn(mMetricsReporter);
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testGetSuggestionRank() {
+        // Setup the section list the following way:
+        //
+        //  Item type | local rank | global rank
+        // -----------+------------+-------------
+        // HEADER     |            |
+        // ARTICLE    | 0          | 0
+        // ARTICLE    | 1          | 1
+        // ARTICLE    | 2          | 2
+        // HEADER     |            |
+        // STATUS     |            |
+        // ACTION     | 0          |
+        // BOOKMARK   | 0          | 3
+        // BOOKMARK   | 1          | 4
+        // BOOKMARK   | 2          | 5
+        // BOOKMARK   | 3          | 6
+        List<SnippetArticle> articles =
+                registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 3);
+        registerCategory(mSuggestionSource, KnownCategories.DOWNLOADS, 0);
+        List<SnippetArticle> bookmarks =
+                registerCategory(mSuggestionSource, KnownCategories.BOOKMARKS, 4);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+
+        assertThat(articles.get(0).getGlobalRank(), equalTo(0));
+        assertThat(articles.get(0).getPerSectionRank(), equalTo(0));
+        assertThat(articles.get(2).getGlobalRank(), equalTo(2));
+        assertThat(articles.get(2).getPerSectionRank(), equalTo(2));
+        assertThat(bookmarks.get(1).getGlobalRank(), equalTo(4));
+        assertThat(bookmarks.get(1).getPerSectionRank(), equalTo(1));
+
+        // Test ranks after changes: remove then add some items.
+        @SuppressWarnings("unchecked")
+        Callback<String> cb = mock(Callback.class);
+        sectionList.dismissItem(2, cb);
+
+        // Using sublists to skip the first items and avoid using existing ones
+        List<SnippetArticle> newArticles =
+                createDummySuggestions(5, KnownCategories.ARTICLES).subList(3, 5);
+        List<SnippetArticle> newBookmarks =
+                createDummySuggestions(6, KnownCategories.BOOKMARKS).subList(4, 6);
+
+        sectionList.onMoreSuggestions(KnownCategories.ARTICLES, newArticles);
+        sectionList.onMoreSuggestions(KnownCategories.BOOKMARKS, newBookmarks);
+
+        // After the changes we should have:
+        //  Item type | local rank | global rank
+        // -----------+------------+-------------
+        // HEADER     |            |
+        // ARTICLE    | 0          | 0
+        // ARTICLE    | 1          | 1
+        //            | -          | -  (deleted)
+        // ARTICLE    | 3          | 7  (new)
+        // ARTICLE    | 4          | 8  (new)
+        // HEADER     |            |
+        // STATUS     |            |
+        // ACTION     | 0          |
+        // BOOKMARK   | 0          | 3
+        // BOOKMARK   | 1          | 4
+        // BOOKMARK   | 2          | 5
+        // BOOKMARK   | 3          | 6
+        // BOOKMARK   | 4          | 9  (new)
+        // BOOKMARK   | 5          | 10 (new)
+
+        // The old ranks should not change.
+        assertThat(articles.get(0).getGlobalRank(), equalTo(0));
+        assertThat(articles.get(0).getPerSectionRank(), equalTo(0));
+        assertThat(articles.get(2).getGlobalRank(), equalTo(2));
+        assertThat(articles.get(2).getPerSectionRank(), equalTo(2));
+        assertThat(bookmarks.get(1).getGlobalRank(), equalTo(4));
+        assertThat(bookmarks.get(1).getPerSectionRank(), equalTo(1));
+
+        // New ranks take into account the previously existing items.
+        assertThat(newArticles.get(1).getGlobalRank(), equalTo(8));
+        assertThat(newArticles.get(1).getPerSectionRank(), equalTo(4));
+        assertThat(newBookmarks.get(1).getGlobalRank(), equalTo(10));
+        assertThat(newBookmarks.get(1).getPerSectionRank(), equalTo(5));
+    }
+
+    @Test
+    @Feature({"Ntp"})
+    public void testGetActionItemRank() {
+        registerCategory(mSuggestionSource, KnownCategories.ARTICLES, 0);
+        registerCategory(mSuggestionSource,
+                new CategoryInfoBuilder(KnownCategories.DOWNLOADS).withViewAllAction().build(), 3);
+
+        SectionList sectionList = new SectionList(mNtpManager, mOfflinePageBridge);
+        bindViewHolders(sectionList);
+
+        assertThat(sectionList.getSectionForTesting(KnownCategories.ARTICLES)
+                           .getActionItem()
+                           .getPerSectionRank(),
+                equalTo(0));
+        assertThat(sectionList.getSectionForTesting(KnownCategories.DOWNLOADS)
+                           .getActionItem()
+                           .getPerSectionRank(),
+                equalTo(3));
+    }
+
+    private static void bindViewHolders(InnerNode node) {
+        bindViewHolders(node, 0, node.getItemCount());
+    }
+
+    private static void bindViewHolders(InnerNode node, int startIndex, int endIndex) {
+        for (int i = startIndex; i < endIndex; ++i) {
+            node.onBindViewHolder(
+                    makeViewHolder(node.getItemViewType(i)), i, Collections.emptyList());
+        }
+    }
+
+    private static NewTabPageViewHolder makeViewHolder(@CategoryInt int viewType) {
+        switch (viewType) {
+            case ItemViewType.SNIPPET:
+                return mock(SnippetArticleViewHolder.class);
+            case ItemViewType.HEADER:
+                return mock(SectionHeaderViewHolder.class);
+            case ItemViewType.STATUS:
+                return mock(StatusCardViewHolder.class);
+            case ItemViewType.ACTION:
+                return mock(ActionItem.ViewHolder.class);
+            case ItemViewType.PROGRESS:
+                return mock(ProgressViewHolder.class);
+            default:
+                return mock(NewTabPageViewHolder.class);
+        }
+    }
+}